Domestic and industrial electric power is generally provided by thermal, hydroelectric, and nuclear power plants. New developments in hydroelectric power plants are capable of responding rapidly to power consumption fluctuations, and their outputs are generally controlled to respond to changes in power requirements. However, the number of hydroelectric power plants that can be built is limited to the number of prospective sites. Thermal and nuclear power plants are typically running at maximum or near maximum capacity. Excess power generated by these plants can be stored via pump-up storage power plants, but these require critical topographical conditions, and therefore, the number of prospective sites is determined by the available terrain.
New technological innovations and ever increasing demands in electrical consumption have made wind power plants a viable option. The power output from an individual wind turbine generator or set of wind turbine generators varies as a function of wind speed. Wind speed is stochastic in nature and varies by hour, by day, by season and by year, and this reduces the availability or firmness of the resource. The power output cannot be dispatched, and its value is therefore discounted. DC wind turbine generators have advantages over AC wind turbine generators in that they are less expensive, lighter, and require less maintenance.
Vanadium redox batteries (VRBs) have recently received favorable attention, as they promise to be inexpensive and possess many features that provide for long life, flexible design, high reliability, and low operation and maintenance costs. A VRB includes cells holding anolyte and catholyte solutions separated by an energy conversion mechanism. VRBs rely on a pumping flow system to pass the anolyte and catholyte solutions through the cells. In operating a VRB, flow rates, internal temperatures, pressure, charging and discharging times are all factors that influence power output.
VRBs can increase power availability and enhance the value and price that can be charged for wind energy. VRBs provide power output to support machine generators and receive excess power to enable charging. A VRB has a unique 1 to 1 charge-discharge response allowing the VRB to absorb energy from wind gusts and thus smooth out the wind power supply. This allows “spillage” of wind energy in wind turbine generators to be reduced to zero and simplifies the control of the blade pitch angles and yaw control of the wind turbine generator and allows the turbine generator to continuously operate at maximum speed.
Thus, it would be an advancement in the art to provide a stable and constant power output from a wind turbine generator by employing the benefits of a VRB.